Some people say that, when you are copying or downloading a copyrighted thing such as music, indeed you are steal it, because you used it without authors permission. This people say that, if every music can be downloaded or copied, there will not be any interest remain for those want to create music without earning any money. This may cause to depletion of cultural staff in the society and will have bad effect obviously. In fact, by using punishment for this manner you are combating with music robbery, such as any other robbery.
But the others argue that you cannot publish the culture or music only by get money. It a poor person copy a music just for hearing or accompanying with the others in the society he/she is not a thief. They believe that some company as a sponsor must help this people and buy music for them because they need it as the others do. Additionally authors must not just think to amount of CDs that has been sold, but also they must think to participate more people in their fan. This approach could bring them more sponsor, and also more money in the future.
All in all I think if we pay for music we understand its worth better, moreover the right of the author will be observed. But there must be some free music for spreading for everyone just for increasing our society general understanding. Maybe by this way we can discover some new capacity.